About the best thing to be said about Barry Sonnenfeld's formulaic comedy of family dysfunction is that once you get past the lengthy, graphic geyser-of-liquid-excrement gag, it's not as irredeemably vulgar as it might have been. Overworked soda company marketing executive Bob Munro (Robin Williams) is scheduled to take his pampered, high-strung wife, Jamie (Cheryl Hines), and children on a summer vacation, but at the last minute his tyrannical, significantly younger boss, Todd Mallory (Will Arnett), demands his presence at a meeting in Colorado that could make or break a deal to take a regional soft drink to the national level. Bob's livelihood is on the line, but he's canceled so many vacations that ditching this one could be the last straw on the home front. So Bob does what his kind do: He shuffles and spins. Bob rents a deluxe camper and tells his bewildered family that there's been a change of plan: Rather than going to the Aloha State with each family member doing his or her own thing like strangers, they're going to take a road trip and enjoy quality togetherness time. The kids — sullen teen-terror Cassie (singer JoJo Levesque) and 12-year-old faux-gangsta Carl (Josh Hutcherson) — are aghast, and Jamie is less than enthusiastic: Her idea of a vacation is time away from her squabbling progeny. And naturally, Bob keeps the fact that he'll be on a working vacation on the q.t. — deception, after all, is always good for comic complications. But not as good as the aforementioned geyser of human waste, which erupts when Bob and Carl try to siphon off the contents of the RV's septic tank at a desolate campground disposal site. That's also where they meet the Gornickes, a friendly, hospitable, recreational-camping-savvy clan — parents Marie Jo and Travis (Kristin Chenoweth, Jeff Daniels) and kids Earl (Hunter Parrish), Moon (Chloe Sonnenfeld, the director's daughter) and little Billy (Alex Ferris) — who enjoy home cookin', country music and sing-alongs, who home-school their kids, and whom the snooty Munros instantly dismiss as dumb-ass rednecks. The more strenuously the Munros try to avoid the Gornickes, the more often their paths cross, adding to the humiliations occasioned by raucous raccoons, malfunctioning brakes and Bob's rotten road skills. By the time the last prat has fallen, everyone has learned some lessons about tolerance and not being judgmental, frayed relationships have been mended, and "Never Ending Love Song" has been sung twice, complete with enthusiastic yodeling by Broadway veteran Chenoweth. Somewhere, Jack Kerouac is sighing.